摘要
Nb-15W-18Si-xHf(x = 0, 5,10 and 15, mole fraction, %) alloys were prepared by arc melting and then homogenized at 1 750℃for 50 h. The microstructure and mechanical behaviors, such as Vickers hardness, fracture toughness, room- and hightemperature strength of the alloys were investigated. The microstructure of the annealed Nb-15W-18Si-xHf alloys is composed of large primary Nbss dendrite and fine eutectic mixture of Nbss and M5Si3 silicide. Both the hardness and the fracture toughness show an increase tendency at room temperature with increase of Hf content. The 0.2% compressive yield strength,σ0.2 of the alloys with 5 %Hf and 10%Hf are larger than 960 MPa at 1 200℃, and about 500 MPa even at 1 500℃.
Nb-15W-18Si-xHf (x = 0, 5, 10 and 15, mole fraction, %) alloys were prepared by arc melting and then homogenized at 1 750 ℃ for 50 h. The microstructure and mechanical behaviors, such as Vickers hardness, fracture toughness, room- and hightemperature strength of the alloys were investigated. The microstructure of the annealed Nb-15W-18Si-xHf alloys is composed of large primary Nbss dendrite and fine eutectic mixture of Nbss and MsSi3 silicide. Both the hardness and the fracture toughness show an increase tendency at room temperature with increase of Hf content. The 0.2% compressive yield strength, σ0.2 of the alloys with 5 %Hf and 10%Hf are larger than 960 MPa at 1 200 ℃, and about 500 MPa even at 1 500 ℃.
出处
《中国有色金属学会会刊:英文版》
CSCD
2006年第A03期2022-2025,共4页
Transactions of Nonferrous Metals Society of China
基金
Project(50671002) supported by the National Natural Science Foundation of China
关键词
铌合金
微观结构
强度
粗糙度
高温条件
机械性能
Nb-15W-18Si-xHf alloys
niobium
silicide
microstructure
strength
fracture toughness